Connecting rod of a ship's diesel engine

Hello,

At the university in Karlsruhe, there is a cut-away diesel engine piston with a connecting rod from a ship diesel engine. This thing is two stories high. I noticed that the connecting rod is made in two pieces. It has a joint in the middle that is guided by a rail. What is the purpose of this joint? Wouldn't it be possible to save a lot of material, costs, and space by eliminating the joint?

Greetings.
Thomas.

*Assumption:* To ensure that only axial forces act on the piston (to prevent wear)?*Assumption out*

Due to the large stroke, the 'straight' connecting rod would collide with the cylinder walls!

The joint prevents that from happening!

Regards,

Manuel.

Hello Thomas!

I suspect it's what's called a "cross-head" engine.
In this design, the upper part of the piston rod is guided by a linear bearing to ensure that all lateral forces are kept away from the piston. Furthermore, these machines are typically designed for extremely long operating cycles, which supports Manuel Thomas' theory about a collision with the cylinder liner.
These engines achieve very high service lives and efficiencies.

Regards,
Alex.

The main reason for using a crosshead design is to avoid the side forces that would otherwise act on the piston.

This already leads to uneven wear on the cylinder bores in truck engines. In ship diesel engines, the forces would be so great that they would cause damage within a very short time.

The cross-head design is the only way to keep all lateral forces away from the piston.
However, this design is only suitable for low speeds.

CU Gremlin.